Public cloud vs. personal cloud: Which is right for you?

A stolen laptop, a crashed hard drive, a shattered smart phone—these are the things digital nightmares are made of. The good news is that, while we may lose our devices, we can avoid losing the data stored on them. Cloud storage allows us to store our data separately from our fragile devices, safeguarding those precious photos, videos, and documents from unexpected mishaps and letting us access them from other connected devices.

The choice of providers is growing, and cloud storage has gotten cheaper. Some even offer free storage, though the amount of storage they provide at no charge may be limited. 

But going to a provider isn’t the only way to store data on the cloud. Depending on your needs, you may want to consider setting up a personal cloud.

Unlike public cloud-storage services such as DropBox and Google Drive, a personal cloud is owned and controlled by you: Instead of leasing space online, you buy a storage system and connect it to the Internet. Not long ago, setting up a personal cloud storage system would have essentially required you to build a server. But now, thanks to consumer-friendly systems from D-Link, Western Digital, and Seagate, among others, you need to do little more than plug the device in.

While essentially performing the same function, these two types of cloud storage have different benefits and drawbacks. So how to choose? The answer may be to set up a private cloud for all your files—and also use a public cloud service (whichever is offering the most free space) for times when you want to share and collaborate on files. This gives you the best of both worlds without having to pay for both.

Here’s a rundown of the most significant differences.

—Karim Lahlou

Pricing and storage capacity

A big plus for public cloud services is that they’re relatively cheap and often free at the lowest tiers of storage. For instance, Google Drive and Microsoft's OneDrive come with 15GB of storage right off the bat. For those who would like to back up relatively lightweight files, 15GB is enough. If you want to store videos or back up your hard drive, though, you’ll need a subscription that starts at $1.99 a month for 100GB.

For personal clouds, there is no subscription charge; you buy the amount of space you need upfront. The current offerings for personal storage devices run in the 2TB to 8TB range (a terabyte is 1,024 gigabytes; see image below).

Here are the pricing and storage pros and cons:

For more information, please check out our guide to Internet Security.

Privacy and security

Reports of government surveillance and data breaches are a constant reminder of the security and privacy risks associated with public storage providers. Your storage provider may also host your data on servers outside of the United States, which makes your data subject to another nation’s privacy laws—laws that you may not agree with (for example, Microsoft’s enterprise-level Azure cloud service lets you decide where your data is stored, but this is not true for its consumer-level OneDrive service).

Personal clouds give you far greater control over your data. As the steward of your own storage, you decide who has access to your data and who doesn’t, and you don’t have to worry about your storage provider collecting information about your activities. Hackers tend to cast wide nets by targeting large data centers, which makes your small personal cloud far less vulnerable to external threats.

Reliability

Just as books and manuscripts are susceptible to wear and tear, abandonment, and weather-related incidents, so is your data. In the summer of 2012, Amazon’s North Virginia data center suffered a power failure that temporarily brought down access to Netflix, Pandora, and Instagram—and its public storage systems. And last year, Nirvanix, a cloud storage company, filed for bankruptcy and gave its customers two weeks to export their data. While these incidents do occur, cloud storage systems are generally reliable, and the likelihood of completely losing your data is rare.

With personal clouds, a thunderstorm in another state won’t prevent you from accessing your files. But hard drive failure is a real threat. According to a study by Backblaze, the failure rate of hard drives is 20 percent during the first four years, and, while there is no definitive proof of failure rate beyond four years, it could be as much as 50 percent after first six years. You could prepare for hard drive failure by backing up your personal cloud, which would require the purchase of more hard drive storage.

Sharing and data migration

In addition to being able to access your data from anywhere in the world, the appeal of cloud-based storage also lies in its sharing capabilities. Public cloud storage providers such as Google Drive and OneDrive allow you to simultaneously collaborate on the same documents, and they also offer shared folders where you can drop files for others to access, and vice versa. Although public cloud storage systems give you a lot of options to share your data, transferring data between providers is surprisingly difficult.

On the other hand, moving your data from a personal cloud to a network hard drive, such as the one in your computer, is simply a matter of plugging in a USB or Ethernet cable. But sharing options are more limited, as most personal cloud storage providers only allow shared folders.

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